Stepladders and structural components thereof



Oct. 24, 1961 c. E. LARSON 3,005,513 STEPLADDERS AND STRUCTURALCOMPONENTS THEREOF Filed March 25. 1959 2 Sheets-Sheet 1 INVENTOR.CLAYTON E LARSON M e/41m,

A TTORNE Y Oct. 24, 1961 c. E. LARSON 3,005,513

STEPLADDERS AND STRUCTURAL COMPONENTS THEREOF Filed March 25. 1959 2Sheets-Sheet 2 INVENTOR. CLAYTON LARSON MM/QM,

ATTORNEY United States Patent 3,005,513 STEPLADDERS AND STRUtITURALCOIVHO- NENTS THEREQF Clayton E. Larson, Weston, COHXL, as'signor toWhite Metal Rolling 8; Stamping Corporation, Brooklyn,

N.Y., a corporation of New York Filed Mar. 25, 1959, Ser. No. 801,751 2Claims. (Cl. 182-165) This invention relates to stepladders andstructural components of ladders and is more particularly concerned withstepladders possessing the characteristics of structural and mechanicalsimplicity, light-weight, economy of manufacture and compactness forstorage.

Field of invention There exists a real consumer demand for a stepladderproviding structural simplicity, stability, minimal weight andcompactness for storage and which does not include spreaders because ofthe attendant hazard of malfunction of spreader elements or collapse ofa spreader retained ladder structure. Use of spreaders in ladders arealso a problem because they contribute to increased bulk, multiplicityof manufactured units and difficulty in converting the ladder from afolded to an open position. Further, ladder spreaders present variousproblems of design and economy in the manufacture of stepladders.

A solution to this situation is provided by the present invention whichoffers a stepladder without the necessity for spreader means.

Another problem attendant upon the manufacture and use of ladders ingeneral, lies in achieving an attachment between the steps and siderails of ladders which will resist both torsional and direct forces.This problem is pronounced in the fabrication of ladders from extrudedlight metals wherein the side rails and steps are commonly formed fromlight weight channel members. A remedy for this situation is offered bythe present invention in which at novel tread and uniting arrangementprovides a stronger connection and more stable structure.

Still another difficulty encountered in the fabrication of stepladdersis that of uniting the front and rear sections by means which will allowpivotal movement between these sections while enduring considerableamounts of strain and wear. A novel lug member provided by the presentinvention provides a solution for this problem.

Objects A principal object of this invention is to provide newimprovements in ladders. Further objects include: the decrease ofmaterial requirements for manufacture; provision for a ladder ofstructural simplicity; increased ease of manufacture as the result ofthe curtailment of the number of necessary structural units and assemblyopera,- tions required; economic benefits resulting from the diminishingof assembly and material requirements; elimination of the possibility ofmechanical malfunction present in stepladders utilizing spreader means;enhancement of stepladder storage characteristics; elimination of thedifliculties presented by the setting up and folding of stepladdersequipped with spreaders; provision of a strong and stable union betweenthe steps and side rails of ladders in general and between the front andrear sections of stepladders, and enhancement of the tractive andcushioning support of ladders.

Other objects and further scope of applicability of the presentinvention will become apparent from the detailed description givenhereafter. 'It should be understood, however, that the detaileddescription, while indicating preferred embodiments of the invention, isgiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

General description These objects are accomplished according to thepres-,

ent invention by forming a stepladder comprising a front section, a rearpropping section and uniting means which serves to pivotally attach thefront and rear sectionsqin.

provides a stepladder structure which may assume a com-.

pact or folded position in which the side rails of the two sections areparallel, or the sections may be spread apart to form an acute angle.When the sections are spread in order to place the ladder in a} stable,independent posi tion for use, the upper ends of the rear section siderails, which are angular, abut upon the rear edges of the upper ends ofthe front section side rails, thereby acting as a stop means to limitthe rotation of the front and rear sections about the point of pivotalattachment andeliminating the necessity for manipulation or adjustmentof spreader means.

The uniting member by which the front and rear sections are connected isfashioned in the form of a lug with a projecting lateral flange whichmay be attached to the rear edge of the front section side rails. Theupper ends of the rear section side rails are pivotally attached to thelug member which extends rearwardly of the front sec-.

tion side rails and the forward portion of the lug plate is fixed to thelateral surface of the front section side rail.- I Brace means areprovided for the front and rear sec! tions. In the preferred form thefront section is braced by means of elongate elements connecting thefront edge.

of the front section side rails with the front, edge of the steps andthe rear section is also reinforced by means Detailed description A morecomplete understanding of the'new devices of this invention may be hadby reference to the accompanying drawings in which:

. FIGURE 1 is a perspective view of a preferred form of stepladder whichis set up on position for use;

FIGURE 2 is a side View of the same ladder in a folded position; v

FIGURE 3 is a fragmentary, enlarged perspective view of an end portionof a step of the ladder;

, FIGURE 4 is an enlarged sectionalview of the lug 7 member and siderails taken along line URE 2;

FIGURE 5 is an enlarged, view of the step. and side'rail;

of FIG- fragmentary perspective FIGURE 6 is an end view ofa lug memberof theladder; y v FIGURE 7 is a fragmentary side view ofthe foot memberand side rail, and i FIGURE 8 is a fragmentary, sectional, end view of,

the bottom of a side rail and the attached foot member; Referring indetail. to the 'drawings, th eistepladder basically comprises a frontsection 2. which includes two Patented Oct. 24, 1961 In this side rails4 with a plurality of space apart steps 6 and a top tread or platform 8fixed between the side rails 4. 7 Attached to the upper ends of thefront side rails 4 are lugmembers 10, described in more detailhereinafter, which are in turn pivotally attached at 1.2 to the siderails 14 of the rear propping section. The rear section side rails 14are provided with angular upper ends 16 which abut upon the rear edge ofthe upper ends of the front section side rails when the ladder structureis in aspread or open position as illustrated in FIGURE 1.

- The rear section side rails 14 are also provided with two "or morebracernembers 1-8 which serve to hold the side rails 14 in aspaced-apart relation. In a preferred form wherein the side rails 14 arechannel members comprising a central web and two spaced-apart laterallyprojecting flanges, one of the brace members 18- is attached at one endto the front flange of the left rear section side rail 14 near the topthereof and at the other end to the from flange of the right rearsection side rail 14 near the bottom thereof. The second brace member 18is attached at one end to the front flange of the night rear sectionside rail 14 near the top thereof and at the other end to the frontflange of the left rear section side rail near thebot'tom thereof. Thetwo brace elements are then attached, such as by rivets, to one anotherat their point of intersection. As shown in FIGURE 1, a second pair ofbrace members '19 may then be similarly attached to the rear flanges ofthe right and left rear section side rails 14.

Additional brace elements may also be provided in order to enhance thestability of the front section 2. The brace elements 20 may be attachedat one end to the front edge of the side rail 4 at a point below thejuncture of the side rail '4 and the bottom step 6, and at the other endto the front edge of the step 6 equal to the distance from this junctureto the point of attachment of the other end of the brace element to theside rail 4.

'- The stepladder may be converted to a compact folded form for'storagein which the front and rear sections are parallel as shown in FIGURE '2,by rotating the rear section side rails 14 about their point of pivotalattachment 12,'toward the front section side rails 4.

"A preferred form of step for use in the invention and in ladders ingeneral is illustrated by FIGURES 3 and 5. The step comprises a channelmember including a central web 2.2mm spaced-apart lateral projections 24which are formed integrally with the web 6 and extend at an anglethereto. If desiredportions of the web 22 may be made to project beyondthe flanges 24 as shown at 26 in FIGURE 5, by setting in the point ofjuncture of the flanges 24 with the central web 6. The end portions ofthe web 22- are provided with recesses 25 as shown in FIGURE 3, wherebythe side rails, as shown by phantom lines in FIGURE 3, may be insertedin the recesses 25 and attached to the lateral flanges 24 of the step byrivets 3'2 which'extend through holes 30.

To enhance the tractive qualities of steps 6, their upper surfaces areprovided with serrations 38' at the front and 7 rear edges.

The lug member used for pivotally uniting the front and rear laddersections is illustrated by FIGURES 4 and 6, and comprises a flat plateand a laterally projecting flange 44 formed integrally therewith. In apreferred form the lug member is provided with a groove 42 along thepoint of juncture of the flange 44 and the plate 10 on the side of theflange which engages the front side rail 4. As shown in FIGURE 4,'the'front side rail 4 is'attached to the plate 10 and the flange 44bymeans such as bolts or rivets. 34 and 36. The rear end of plate It) isattached to rear side rail 14 by pivotal means 12.

To prevent marring and provide a tractive support surfgce for the ladderstructure, foot elements illustrated by FIGURES 7 and 8 are provided.For descriptive purposes the foot element is depicted in conjunctionwith front side rail 4. The foot elements comprise an L- shaped member46 which is attached to the side rail 4 by rivet 52 and to secure astronger attachment a groove 54 is provided adjacent to the verticalprojection of the foot element 46 to receive the bottom of the side rail4.

In the bottom surface of the horizontal projection of member 46, aresilient element 48 made of rubber or a similar substance, is insertedin the recess 56 and secured there by a rivet or similar means 50.

Having provided a complete description of the invention in such manneras to distinguish it from other inventions and from what is old, andhaving provided a description of the best mode contemplated of carryingout the invention, the scope of patent protection to be granted theinvention is defined by the following claims.

I claim:

1. A stepladder comprising a front section including two side rails eachcomprising a central web, two spacedapart lateral projections formedintegrally with said web which parallel the longitudinal axis of the Weband are normal to the web, means for connecting said two side rails inspaced-apart relation comprising a step including a central web, twospaced apart lateral projections formed integrally with said web whichparallel the longitudinal axis of the web and project at an angle to theweb, said central web being provided at each end with recessesspaced-apart a distance equal to the distance between said spaced-apartlateral projections of said side rails so that the lateral projectionsof the side rails may be inserted within the recesses provided in thecentral web of the step and attached to the lateral projections of thestep, additional steps similarly fixed in a spaced-apart relationbetween said two side rails, a rear propping section comprising two siderails with angular upper ends, brace means for holding said rear sectionside rails in spaced-apart relation, means for pivotally attaching saidrear section is said front section comprising a lug member carried nearthe top of one of the side rails of the front section and extendingrearwardly of the rear edge of the side rail with one of the side railsof the rear section being pivotally connected thereto, a second lugmember similarly attached to the other side rail of the front sectionand pivotally connected to the second side rail of the rear section,said lug members being spaced from the top of the front and rear sectionside rails so that the rear section side rails may be moved about thepoint of pivotal attachment to engage the angular upper ends of the rearsection side rails with the rear edges of the front section side railsthroughout a substantial extent of the angular surface and actingas thesole stop means for the rear propping section.

2. In a ladder having side rails comprising a central web andspaced-apart lateral projections formed integrally with the 'web, a stepcomprising a central web, two spaced-apart lateral projections formedintegrally with said web which parallel the longitudinal axis of the weband project at an angle to the web, said central web being provided ateach end with recesses spaced-apart a distance equal to the distancebetween said spaced-apart lateral projections of said side rail so thatthe lateral projections of the side rail may be inserted within therecesses provided in the end of the central web of the step and attachedto the lateral projections of the step.

References Cited in the file of this patent UNITED STATES PATENTS UNITEDSTATES PATENT OFFICE CERTIFICATION OF CORRECTION Patent N05 3,,OO5,,513October 24 1961 Clayton E. Larson It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column 4 line 36 for "is" read to Signed and sealed this 24th day ofApril 1962 (SEAL) Attest:

ESTON G. OHNSON DAVID La LADD Attesting Officer Commissioner of Patents

